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We have measured the muon flux and production rate of muon-induced neutrons at a depth of 611 m water equivalent. Our apparatus comprises three layers of crossed plastic scintillator hodoscopes for tracking the incident cosmic-ray muons and 760 L of a gadolinium-doped liquid scintillator for producing and detecting neutrons. The vertical muon intensity was measured to be Iμ=(5.7±0.6)×10-6 cm-2 s-1 sr-1. The yield of muon-induced neutrons in the liquid scintillator was determined to be Yn=(1.19±0.08(stat)±0.21(syst))×10-4 neutrons/(μ·g·cm-2). A fit to the recently measured neutron yields at different depths gave a mean muon energy dependence of 0.76±0.03 for liquid-scintillator targets.

Purpose: The purpose of this study is to review the result of patients with Bosworth fracture dislocation of ankle. Type Of Study: Retrospective case series. Methods: Four patients with Bosworth fracture-dislocation of ankle are evaluated clinically and radiologically. Result: All four cases have failed initial closed reduction of the ankle and open reduction is required. Three patients with delayed presentation suffered from post-traumatic ankle stiffness and subsequently developed ankle degeneration. Conclusion: Early recognition and prompt reduction of the dislocated ankle is important in case of Bosworth fracture dislocation in order to prevent late complication. Closed reduction of dislocated ankle is usually not helpful and repeated attempts may be harmful. Emergency operation of open reduction and internal fixation is usually required to reduce the ankle joint without delay. [ABSTRACT FROM AUTHOR]

Post-traumatic premature closure of distal fibular growth plate is a rare entity and results in shortened lateral malleolus. This can lead to lateral wedging of distal tibial epiphysis, valgus ankle and medial ankle instability. Ramsey and Hamilton noted experimentally that loss of fibular length caused a dramatic lateral shift in tibiotalar surfaces. Even a displacement of as little as 1 mm will distort the areas of tibiotalar contact and lead to early joint degeneration. Colton believed it is due to the oblique articular surface of the malleolus is no longer closely applied to the talus. We present a case of premature closure of distal fibular physis with lateral malleolar shortening. Ankle arthroscopy demonstrated syndesmosis instability resulted from shortened lateral malleolus and stability restored after fibular lengthening. [ABSTRACT FROM AUTHOR]

Background: The purpose of this registry-based retrospective study was to investigate the risk factors related to one-year mortality in displaced intracapsular fragility hip fracture patients., Methods: Patients were screened from the Fragility Fracture Registry. Inclusion criterion was displaced intracapsular hip fracture patients with atypical or pathological fractures excluded. One-year mortality was investigated against risk factors including age, gender, past medical history, pre-fracture mobility (PFM), pre-operation ASA grade, delayed surgery over 48 h, post-surgical complications, and length of stay at acute orthopedic ward (LOS)., Results: A total of 1050 patients were included for further analysis. Gross one-year mortality was 14.9%. One-year mortality was significantly higher in patients who received non-operative treatment and those who received surgery but delayed over 48 h after admission (both p <  0.001). Male gender (OR = 2.708), advanced age (OR = 1.359), higher risk ASA grades (III to V) (OR = 1.990), past history of gastrointestinal disease (OR = 1.671), and renal impairment (OR = 1.984) were related to higher one-year mortality. The mortality of patients in PFM grade 3 and LOS group 3 was significantly higher (OR = 2.240 and 1.722, respectively)., Conclusions: Higher age, male gender, past gastrointestinal disease and renal impairment, ASA grade over 3, indoor confined pre-fracture ambulatory, and stay at hospital over 15 days were risk factors related to higher one-year mortality in surgically treated displaced intracapsular hip fracture patients. A multi-disciplinary approach is advised to patients identified with these risks factors and co-managed by orthopedic surgeons, geriatricians, and fracture liaison nurses.

Identification of the correct source of symptoms is the key in formulating the correct treatment plan for heel pain after calcaneal malunion. Calcaneofibular and posterior ankle impingements can occur due to malunion of a joint depressed-type calcaneal fracture. The purpose of this Technical Note is to report the technical details of posterior and lateral decompression through the posteromedial and posterolateral portals using posterior ankle endoscopy.

Post-traumatic peroneal tendon subluxation or dislocation is most commonly due to injury to the superior peroneal retinaculum. Acute repair of the retinaculum is an option for active athletes who desire quick return of sport activity. In general, conventional open surgeries require extensive exposure of the injured superficial peroneal retinaculum and have potential risks of scar formation, sural nerve injury, limited range of movement, peroneal tendon re-subluxation, and tendon irritation. The purpose of this Technical Note is to describe the details of endoscopic superior peroneal retinaculum reconstruction. This has the advantages of minimally invasive surgery of better cosmesis, less soft tissue dissection, less postoperative pain, less peritendinous fibrosis, and less subjective tightness at peroneal tendons. The endoscopic view allows better assessment of retinaculum integrity, grading of injury, and detection of coexisting pathology.

Introduction: In setting up a disease registry for fragility fractures in Hong Kong, we conducted a retrospective systematic study on the management of fragility hip fractures. Patient outcomes were compared with the standards from our orthopaedic working group and those from the British Orthopaedic Association that runs a mature fracture registry in the United Kingdom., Methods: Clinical data on fragility hip fracture patients admitted to six acute major hospitals in Hong Kong in 2012 were captured. These included demographics, pre- and post-operative assessments, discharge details, complications, and 1-year follow-up information. Analysis was performed according to the local standards with reference to those from the British Orthopaedic Association., Results: Overall, 91.0% of patients received orthopaedic care within 4 hours of admission and 60.5% received surgery within 48 hours. Preoperative geri-orthopaedic co-management was received by 3.5% of patients and was one of the reasons for the delayed surgery in 22% of patients. Only 22.9% were discharged with medication that would promote bone health. Institutionalisation on discharge significantly increased by 16.2% (P<0.001). Only 35.1% of patients attended out-patient follow-up 1 year following fracture, and mobility had deteriorated in 69.9% compared with the premorbid state. Death occurred in 17.3% of patients within a year of surgery compared with 1.6% mortality rate in a Hong Kong age-matched population., Conclusions: The efficiency and quality of acute care for fragility hip fracture patients was documented. Regular geri-orthopaedic co-management can enhance acute care. Much effort is needed to improve functional recovery, prescription of bone health medications, attendance for follow-up, and to decrease institutionalisation. A Fracture Liaison Service is vital to improve long-term care and prevent secondary fractures.

A 7-year-old girl presented with a 2-day history of acute neck pain without any preceding injury. The pain was around the left posterior paraspinal muscle and was aggravated by neck movement. There was no neurological abnormality; white cell count and inflammatory markers were slightly elevated. Radiology of the cervical spine showed calcification of C3/4 and C4/5 discs as well as the posterior longitudinal ligament over C3/4. She was treated conservatively with a neck collar and Panadol syrup. No non-steroidal anti-inflammatory drug was prescribed. Two months later, calcification of the posterior longitudinal ligament had resolved and calcification at C3/4 and C4/5 discs and the C4 lower endplate had decreased. After one year, she was painfree with no tenderness over her neck and had full range of neck motion and complete resolution of the calcification.

Background: The elbow is an important but complex structure, with movement in both the sagittal plane in flexion and extension, as well as the rotational plane in forearm supination and pronation. Trauma is a common cause of elbow stiffness, which significantly hampers daily function. There are currently no gold-standard management guidelines for post-traumatic elbow stiffness, and most of the published literature focuses solely on the sagittal plane of motion., Methods: This is a retrospective case series reviewing all patients who underwent a surgical release for treatment of post-traumatic elbow stiffness during a 36-month period. Motion range and the shortened version of the Disabilities of the Arm, Shoulder and Hand scores were serially measured and analyzed., Results: The results obtained showed that both the sagittal and rotational range of motion directly influenced upper limb function; however, the relationship between these two motion planes was weak, meaning that both sagittal and rotational motion in the elbow need be addressed individually. Post-traumatic elbow stiffness could be aptly managed by various surgical approaches, including arthroscopic-assisted procedures; these were all effective in increasing both the sagittal and rotational range of motion. More importantly, this gain in range translated to a statistically significant improvement in upper limb function., Conclusions: Management of elbow stiffness needs to be tackled in both the sagittal and rotational motion planes.

A measurement of the energy dependence of antineutrino disappearance at the Daya Bay reactor neutrino experiment is reported. Electron antineutrinos (ν¯(e)) from six 2.9  GW(th) reactors were detected with six detectors deployed in two near (effective baselines 512 and 561 m) and one far (1579 m) underground experimental halls. Using 217 days of data, 41 589 (203 809 and 92 912) antineutrino candidates were detected in the far hall (near halls). An improved measurement of the oscillation amplitude sin(2)2θ(13)=0.090(-0.009)(+0.008) and the first direct measurement of the ν¯(e) mass-squared difference |Δm(ee)2|=(2.59(-0.20)(+0.19))×10(-3)  eV2 is obtained using the observed ν¯(e) rates and energy spectra in a three-neutrino framework. This value of |Δm(ee)2| is consistent with |Δm(μμ)2| measured by muon neutrino disappearance, supporting the three-flavor oscillation model.

The Daya Bay Reactor Neutrino Experiment has measured a nonzero value for the neutrino mixing angle θ(13) with a significance of 5.2 standard deviations. Antineutrinos from six 2.9 GWth reactors were detected in six antineutrino detectors deployed in two near (flux-weighted baseline 470 m and 576 m) and one far (1648 m) underground experimental halls. With a 43,000 ton-GWth-day live-time exposure in 55 days, 10,416 (80,376) electron-antineutrino candidates were detected at the far hall (near halls). The ratio of the observed to expected number of antineutrinos at the far hall is R=0.940±0.011(stat.)±0.004(syst.). A rate-only analysis finds sin(2)2θ(13)=0.092±0.016(stat.)±0.005(syst.) in a three-neutrino framework.

There is no unified national training system for orthopaedic surgeons in China. With such rapid progress in many aspects of life in China, there is an imminent need for improvement in the training of orthopaedic specialists. Since 2003 the orthopaedic community in Hong Kong has been working in collaboration with their colleagues in mainland China to develop a training system for orthopaedic surgery. We adopted the system from the Royal College of Surgeons of Edinburgh (RCSEd), setting up a trial centre in the Beijing Jishuitan hospital in 2006, with trainers and trainees attaining the standards set by RCSEd and the Hong Kong College of Orthopaedic Surgeons (HKCOS). This trial is ongoing, with the success of two trainees who passed the exit examination in 2010 and became the first Chinese orthopaedic surgeons with a joint fellowship of both the RCSEd and the HKCOS. Following this inaugural success, we are confident that China will develop a training system for orthopaedic surgeons to a consistently high international standard.

Purpose: Our purpose was to evaluate the clinical and radiologic results of arthroscopy-assisted hallux valgus deformity correction with percutaneous screw fixation., Methods: Ninety-four feet underwent arthroscopy-assisted hallux valgus deformity correction. Patients in whom the 1,2-intermetatarsal angle could be reduced manually and who had no significant abnormality of the distal metatarsal articular angle were included, and an endoscopic distal soft tissue procedure was performed. Those patients with first tarsometatarsal hypermobility, in whom the 1,2-intermetatarsal angle cannot be reduced manually, or those who had a significantly abnormal distal metatarsal articular angle were excluded. Patients were assessed using the American Orthopaedic Foot and Ankle Society (AOFAS) hallux-metatarsophalangeal-interphalangeal scale. The pre- and postoperative hallux valgus angle, intermetatarsal angle, distal metatarsal articular angle, and sesamoid position were measured., Results: The mean score on the AOFAS scale was 93 +/- 8 out of 100 points. The hallux valgus angle improved from 33 degrees +/- 7 degrees (range, 20 degrees to 58 degrees ) to 14 degrees +/- 5 degrees (range, 4 degrees to 30 degrees ). The intermetatarsal angle improved from 14 degrees +/- 3 degrees (range, 10 degrees to 26 degrees ) to 9 degrees +/- 2 degrees (range, 5 degrees to 18 degrees ). Complications of hallux varus, skin impingement, screw breakage, and first metatarsophalangeal stiffness were experienced. Two patients with symptomatic recurrence had revision operation performed., Conclusions: Our study shows that arthroscopic correction of the hallux valgus deformity can achieve good clinical and radiologic results, provided that careful preoperative clinico-radiologic assessment is made to exclude patients contraindicated for the procedure., Level of Evidence: Level IV, therapeutic case series.

Objective: This article describes rice bodies found in patients with atypical mycobacterial tenosynovitis and bursitis, emphasizing the sonographic and MR imaging appearances of these small bodies., Conclusion: Rice bodies occur in patients with atypical mycobacterial tenosynovitis and bursitis. When small, rice bodies are better visualized on MR imaging than on sonography, allowing the radiologist to consider appropriate diagnoses.

In children, neuroblastoma can mimic various orthopaedic pathologies and this may create difficulties for doctors in reaching the correct diagnosis. Stage IV neuroblastoma was initially diagnosed as transient synovitis in this case report of a 7-year-old girl presenting with hip and low back pain.

Five cases suffering from unilateral paresthesia over the corner of the mouth and the hand on the same side were examination for cheiro-oral syndrome. Of these, three cases were typical and the other were variant cases associate with transient hemi-signs. Lesion sites were identified by computed tomographic (CT) scan, magnetic resonance imaging (MRI) or both. Of the five patients, lesions were due to thalamic infarction in three cases, pontine hemorrhage in one case, and tumor compression on the right frontoparietal lobe in the last case. The pathophysiology of all cases were classified according to location of the lesion on the thalamus, the pons, and the parietal lobe, which are the usual anatomical sites responsible for this syndrome. Based on the three typical cases and thirteen cases cited from the English literature, a clinical classification has been established. The classification is based on age at the time of onset, gender, lesion site, etiology, risk factors, and certain clinical features. These sixteen cases fell into three distinct groups: a) those in which the thalamic lesions were related to infarction, b) those in which tumors, or in rare cases infarction, were found in the parietal lobe, and c) those in which hemorrhage occurred in the pons. Using this classification, the cheiro-oral syndrome can be more systematically defined.

A prospective study of fifty-two fresh traumatic unstable fractures of the proximal or middle phalanges of the hand in forty-seven patients was reviewed. All the fractures were fixed with A.O. miniature screws and plates. The overall results were not satisfactory and complications were frequent. Only 26.9% of the fractures had good results. Fractures associated with significant soft tissue injuries had very poor results. When the present series was compared with a comparable group of fractures fixed with Kirschner wires, there was no significant improvement in the results. The unsatisfactory outcome of this group of unstable fractures may be largely due to the frequent association with poor prognostic factors.

A splint for controlled active motion after flexor tendon repair is described. It incorporates a single core-coated elastic band passing around a palmar pulley and attached proximally to a spring wire. Its mechanical properties were tested against six other systems. The tension in various systems all rose near full extension. However, the palmar pulley, the spring wire, and the elastic band each could lower the tension significantly. When the bending moments at the interphalangeal joints were measured, all systems produced a peak during the latter part of extension. With the palmar pulley, spring wire, and elastic band, the rise was minimal and in fact, the bending moments diminished near full extension. Initial results in 28 flexor tendon repairs using this splint showed less flexion contracture when compared with 78 flexor tendon repairs using a standard rubber band anchored at the wrist.

We report a prospective study on 284 digital fractures of the hand in 235 patients. Management followed clear guidelines set out in a protocol. Important factors in the selection of the treatment method were, acceptable alignment, functional stability, and associated "significant" soft tissue injuries. "Functionally" stable fractures treated by free mobilization had satisfactory results. Unstable fractures treated by splints or Kirschner wire fixation produced unsatisfactory results. "Open fracture," "comminuted fracture," and "associated significant soft tissue injuries" were identified as unfavorable prognostic factors. The anatomic site of the fractures was not important in determining the final outcome. About 15% of the displaced fractures became functionally stable after closed reduction and their results were comparable with the undisplaced fractures. About 30% of the patients had various degrees of difficulty after they returned to work. About 14% of the patients eventually changed their jobs because of their residual disability.